Parkinson took over in April 2017, and his 2,894 days in charge have nudged him ahead of Graham Heathcote, who served Alty between 2002 and 2010.
The manager has taken the club to new heights and now wants to create history by taking the club into the EFL for the first time.
He knows to do that in the months ahead, an improvement in their form is required.
The club have taken just two points from their last seven games but Parkinson knows they are still within striking distance of the play-offs.
The moment arrived on Saturday in the 2-2 draw with Ebbsfleet and after he said he "of course" believed the side were good enough to make the top seven.
"I'm really pleased that I’ve been able to reach such a milestone in my career,” he told the club’s website, with only the legendary John King has spent more cumulative time in charge over his three spells.
“Managing such an historic club like Altrincham for coming up on eight seasons is something I’m extremely proud of.
"I feel very privileged to be the manager here, and along with my assistant Neil Sorvel, I feel that we’ve delivered on our promise that we made when we joined the football club in getting the club back to the National League.
"We’ve had success season-on-season. Two promotions in three seasons, a number of FA Trophy runs, converting the football club from part-time to full-time, reinvigorating and starting up a new academy, giving young players a platform to make the first team and have successful non-league careers.
"These things are really important to us and we feel we’ve got so much more to achieve at the football club and long may that continue.
"Our families will be really proud of the fact that we’ve hit such a landmark at Altrincham and I hope we can keep pleasing our fans and the board of directors, keep entertaining with the brand of football that Altrincham is now associated with, and hopefully achieve the goal of reaching the football league one day."